<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <!--
        multipart/form-data : 表示当前提交的数据中有二进制数据
     -->
    <form action="upload" method="post" enctype="multipart/form-data">
        <input type="file" name="img"/>
        <input type="submit" value="提交"/>
    </form>

</body>
</html>